The Characteristics of Airflow Limitation and Future Exacerbations in Different GOLD Groups of COPD Patients

Int J Chron Obstruct Pulmon Dis. 2021 May 20:16:1401-1412. doi: 10.2147/COPD.S309267. eCollection 2021.

Abstract

Background: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 separated pulmonary function from combined assessment. We aimed to analyze the characteristics of airflow limitation and future exacerbations in different GOLD groups of chronic obstructive pulmonary disease (COPD) patients.

Methods: For this prospective observational study, stable COPD outpatients were enrolled and divided into Groups A, B, C and D based on GOLD 2017, and followed-up for 18 months. Data on demographics, pulmonary function, COPD assessment test (CAT), Clinical COPD Questionnaire (CCQ), modified Medical Research Council (mMRC), exacerbations, mortality and treatments were collected. A post-bronchodilator ratio of forced expiratory volume in one second to forced vital capacity <0.70 confirms the presence of airflow limitation.

Results: A total of 993 subjects were classified into Groups A (n = 170, 17.1%), B (n = 360, 36.3%), C (n = 122, 12.3%), and D (n = 341, 34.3%). There were significant differences in mMRC, CAT, CCQ, exacerbations and hospitalizations rates among the different groups (P < 0.001). Groups B and D had more severe airflow limitation than Groups A and C (P < 0.05). In the same groups with different severity of airflow limitation, the differences were mainly observed in body mass index, CAT, CCQ and treatment with long-acting muscarinic antagonist (LAMA) and LAMA + long-acting β2-agonist + inhaled corticosteroid (P < 0.05). After 18 months of follow-up, the exacerbations and hospitalizations rates were significantly different among different groups (P < 0.05). However, in the same groups with different airflow limitation severity, the mortality rates and number of exacerbations, hospitalizations and frequent exacerbators showed no differences.

Conclusion: In the GOLD groups, different severity of airflow limitation had no impact on future exacerbations and mortality rate. It implies that pulmonary function is not a good indicator for predicting exacerbation.

Keywords: Global Initiative for Chronic Obstructive Lung Disease; chronic obstructive pulmonary disease; exacerbation; pulmonary function.

Publication types

  • Observational Study

MeSH terms

  • Disease Progression
  • Forced Expiratory Volume
  • Humans
  • Lung
  • Muscarinic Antagonists / adverse effects
  • Pulmonary Disease, Chronic Obstructive* / diagnosis
  • Pulmonary Disease, Chronic Obstructive* / drug therapy
  • Severity of Illness Index
  • Vital Capacity

Substances

  • Muscarinic Antagonists

Grants and funding

This work was supported by grants from the National Natural Science Foundation of China (NSFC, Grants 81770046 to Prof Ping Chen).